The Role Of Heterotrophic Microflagellates In Plankton Communities

In the summer of 1988, under NATO sponsorship, approximately 80 scientists lived and worked together in Plymouth for two weeks to evaluate the ecological role of protozoa in the sea. Through the convivial surroundings, close working conditions and special facilities that had been brought together for NATO ASI 604/87 a 'melting pot' of ideas was formed, which stimulated the multidisciplinary creativity which is expressed in this book and in a second series of papers which will be published in Marine Microbial Food Webs under the title - "Protozoa and their Role in Marine Microbial Food Webs". Discussions of the role of protozoa in the microbial food web, in the cycling of carbon and nitrogen and the extent to which this web acts as a link or sink to metazoa in the water column were major themes of the ASI. Structured sessions covering oral and poster presentations, field work, model 1 ing, laboratory practicals and demonstrations of techniques such as image analysis and flow cytometry, formed the core of the meeting. Participants took part enthusiastically in the practical sessions developing new concepts and obtaining new insights into their work. The practicals included a 'protozoo' and some beautiful films and videos. Field excursions were made to a range of sites including a unique marine sewage farm at Looe in Cornwall, (Jones this volume). Interactive workshops allowed scientists with no modelling experience to input their results to three simulation models and a flow analysis package.

Marine ecosystems are changing at an unprecedented rate. In addition to the direct effects of e.g. warming surface temperatures, the environmental changes also cause shifts in plankton communities. Plankton makes up the base of the marine food web and plays a pivotal role in global biogeochemical cycles. Any shifts in the plankton community composition could have drastic consequences for marine ecosystem functioning. This Research Topic focuses on causes, effects and consequences of such shifts in the plankton community structure.

All relevant ecological aspects of plankton, especially seasonal changes in the species composition, the role of competition for limiting resources in species replacements, the role of parasitism, predation and competition in seasonal succession are treated in detail considering phytoplankton, zooplankton and bacteroplankton. In addition to its use as a valid reference book for plankton ecology, this monograph may well be used as a model for other kinds of ecological communities.

Biological processes in the oceans play a crucial role in regulating the fluxes of many important elements such as carbon, nitrogen, sulfur, oxygen, phosphorus, and silicon. As we come to the end of the 20th century, oceanographers have increasingly focussed on how these elements are cycled within the ocean, the interdependencies of these cycles, and the effect of the cycle on the composition of the earth's atmosphere and climate. Many techniques and tools have been developed or adapted over the past decade to help in this effort. These include satellite sensors of upper ocean phytoplankton distributions, flow cytometry, molecular biological probes, sophisticated moored and shipboard instrumentation, and vastly increased numerical modeling capabilities. This volume is the result of the 37th Brookhaven Symposium in Biology, in which a wide spectrum of oceanographers, chemists, biologists, and modelers discussed the progress in understanding the role of primary producers in biogeochemical cycles. The symposium is dedicated to Dr. Richard W. Eppley, an intellectual giant in biological oceanography, who inspired a generation of scientists to delve into problems of understanding biogeochemical cycles in the sea. We gratefully acknowledge support from the U.S. Department of Energy, the National Aeronautics and Space Administration, the National Science Foundation, the National Oceanic and Atmospheric Administration, the Electric Power Research Institute, and the Environmental Protection Agency. Special thanks to Claire Lamberti for her help in producing this volume.

Introduction This book contains papers given at a NATO Advanced Research Institute (A.R.I.) held at Caiscais, Portugal, in November, 1981. The subject of the A.R.I. was marine heterotrophy; this is defined as the process by which the carbon autotrophically fixed into organic compounds by photosynthesis is transformed and respired. Obviously all animals and many microbes are heterotrophs but here we will deal only with the microbes. Also, we restricted the A.R.I. primarily to microbial heterotrophy in the water column even though we recognize that a great deal occurs in sediments. Most of the recent advances have, in fact, been made in the water column because it is easier to work in a fluid, apparently uniform medium. The reason for the A.R.I. was the rapid development of this subject over the past few years. Methods and arguments have flourished so it is now time for a review and for a sorting out. We wish to thank the NATO Marine Science Committee for sharing this view, F. Azam, A.-L. Meyer-Reil, L. Pomeroy, C. Lee, and B. Hargrave for organizational help, and H. Lang and S. Semino for valuable editing aid.

This volume provides the first cohesive and authoritative account of this important field. The book will be of interest to protozoologists, protistologists, evolutionary biologists, and ecologists dealing with aquatic or soil ecosystems.

Eutrophication in the transitional marine coastal waters has increased dramatically in many parts of the world, and this evolution has shifted attention to the anthropogenic factor. The problem has become the theme of many conferences and workshops, as well as being given priority in international organizations. This volume has been brought about by the desire to assess both our scientific understanding as well as the means and technologies available to combat the problem of marine coastal eutrophication. It discusses the results of research and surveillance programmes carried out in the last decades, confronting these results with experience gained elsewhere, and reviewing current proposals of what can be done about the problem. This volume will be invaluable to environmental scientists and marine ecologists, as well as to those who wish to resolve the many large-scale environmental problems, specifically marine eutrophication and marine pollution in general.